Air sterilizer



Aug. 21, 1951 F. H. HAlNEs AIR STERILIZER Filed Deo. 14, 1948 5 Sheets-Shea?l l 67 69 @5Mj u* f 7/ j tu v Il El /73 27V- l 72 27V" 75; if 1, i l

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ATTORNEY F. H. HAINES AIR STERILIZER Aug. 2l, 1951 3 Sheets-Sheet 2 Filed Dec. 14, 1948 Fea/YK h. Hfs/N55.

Aug. 21, 1951 Filed Deo. 14, 1948 3 Sheets-Sheet 5 (E y 1 l' 5 2pm r mlm 24 .77 24 35 r9 I Inh FEA/wa H.. f//a//vs Patented Aug. 21, 1951 AIR STERILIZER Frank H. Haines, Baltimore, Md., as signor to Standard Engineering Company of Washington, D. C., Inc., a corporation of Delaware Application December 14, 1948, Serial No. 65,229

(Cl. B19-39) Y Claims. 1

The present invention relates to improvements in air sterilizers and has for an object the provision of such a device for the killing of any disease carrying germs which are present in the air in hospitals, assembly halls and the like.

Another object of the present invention is to provide an improved structure of this character in which disease carrying germs are destroyed before the air is exhausted into the open atmosphere or recirculated into a building or the fresh air supply into a building.

A further object of the present invention is to provide an improved air sterilizer in which an air diverter is positioned adjacent the inlet of the heating chamber so that the incoming vitiated air is caused to flow into direct contact with the heating units. This is the most restricted portion of the air conduit and imparts to the device the advantage that the heating elements in this area have considerably less space and volume of incoming air to heat so that the temperature of this relatively cool air can be initially raised a relatively large amount. From this restricted area the air conduit gradually increases in size towards the outlet of the sterilizer in order to permit the expansion of the air as it progressively increases in temperature in its passage through the heating chamber.

A still further object of the present invention is to provide an improved device of this character in which the temperature of the germ laden air is raised to the desired degree by two methods of heating which are carried on simultaneously, namely, conduction and convection.

The present invention aims to provide an improved structure which is automatic in operation and has relative few moving parts to wear out and be replaced.

The present invention contemplates in one of its broadest aspects the provision of an improved air sterilizer comprising a casing having an air inlet at one end and an air outlet at its opposite end, a series of spaced apart heating elements disposed within the casing between its inlet and outlet and a diverter for directing the incoming air into direct contact with said heating elements.

It is another aim of the present invention to mount the heating elements and the diverter upon a base plate whichin turn is detachably connected to the casing so that by merely loosening a few bolts the base plate with the heating elements and the diverter mounted thereon can be easily and quickly removed from the casing as a unit for the purpose of making repairs or replacement.

With the foregoing and other objects in view, the invention will be hereinafter more fully described and more particularly pointed out in the appended claims.

In the drawings, in which the same parts are denoted by the same reference numerals through` out the several views;

Figure 1 is a front elevational View of the improved air sterilizer ccnstructed in accordance with' the present invention;

Figure 2 is a side elevational view of the same;

Figure 3 is a vertical sectional view of the improved device with parts in elevation;

Figure 4 is a fragmentary bottom plan view of the base plate;

Figure 5 is a transverse horizontal sectional view on the line 5-5 of Figure 3;

Figure 6 is a vertical sectional view through one of the insulators shown in Figure 5; and

Figure 7 is a fragmentary diagrammatic View of the lower end of the improved device showing the base plate, the heating elements and the diverter partially withdrawn from the casing as an integral unit.

Referring more particularly to the drawings, II) indicates the outer wall of a cylindrical metal casing. The casing includes an inner wall II which is concentric with and spaced from the outer wall I0. A reinforcing band I2 is secured by welding or the like to the inner face of the outer wall I0 at the lower end portion thereof. A similar reinforcing band I3 is secured by welding or the like to the outer face of the inner wall II at the lower end portion thereof. An insulating ring I4 is attached by welding or the like to the lower ends of the walls I0 and II and to the bands I2 and I3 for closing the lower end of the casing. Insulating material I5, such as sheet asbestos or the like, is secured to the under face of the ring I4. The space between the inner and outer walls I0 and II is filled with insulating material I6, such as glass Wool or the like.

A base plate I is detachably connected to the ring I4 by bolts or the like I8 and is provided with an opening through which extends an annulus I9. The lower end portion of the annulus I9 extends below the base plate I and the upper end of the annulus is received by a suitable opening in a circular plate 2U.

Brackets 2l are attached by welding or the like to the under surface of the plate 20 and to the outer face of the annulus I9. Brackets 22 are secured to the under surface of the plate 2G and to the inner face of an upstanding ring 23. Brackets 26 are secured as by welding or the like to the outer face of the ring 23 and the upper surface of the base plate I1.

A top reinforcing band 25 is secured to the inner surface of the upper end portion of the wall I0 and together with the upper end of the wall ID supports a top plate 26, having a suitable opening for the reception of a ring 21 which extends below and above the top plate 26. An annulus comprising a lower annular flange 28,

an upwardly and inwardly inclined wall 29 and an upper annular flange 30 provides a continuation of .thelinner wall Il of the casing. The inner face of theange '28 is securedby welding or the like to the outer surface of the upper portion of the wall I I and the outer face of the flange 30 is secured by welding or the like to the inner surface of the ring 291.

Intermediate its upper and lower-ends Ythe wall I6 has secured to its inner surface areinforcing band 3| and to its outer surfacemounting brackets 32 having suitable openings adapted to receive threaded supporting rods provided with nuts by which the casingr can be suspended from the ceiling of a room. Four vertically extending standards 33 .angularly .spaced apart about ninety degrees .are disposed within the space dened by the wall Il and are spaced inwardly therefrom. The :standards -have `apertured yfeet 34 for the receptionof bolts 35 Ywhich also vkextend. Ythrough the bottom plate l1 .and .the .circular plate 26 and .receive nuts 36 `thereon .for mounting the standards on the .base'plate l1. rIhefbolts V'35 are surrounded :by .spacers '35a.

A set .of vertically .aligned .and vspaced apart supporting rings 31 is secured by .welding or the like fto the .inner faces .of lthe standards 33. A second set of similarl-yiarranged supporting -rings 38 is secured to the youter -faces of the standards 33 in vertically staggered relation to the rings 31. A plurality `of porcelain insulators 39 are mounted on the rings 31 and r36. As shown in Figure 6, each insulator 39 -is substantially H- shaped and has xa rectangularly shaped 4longitudinal groove 40 in its upper surfaceand a similarlyshaped groove V4I in its 'lower surf-ace. -Each insulator has a .square .medially disposed longitudinal passageway 42. As shown in the upper rig-hthand portion of Figure 5, the Aiirst insulator 39 of each concentric -row is -secured to -its Vrespective ring 3-1 and 38 by a bolt 43 and a nut 44 and every -third insulator in each row is similarly attac-hed by -bolts fto its ring. A square shaped tie rod 45 extends th-rough -the passageway 42 of two adjacent runbolted vinsulators 39 and has its opposite end portions received by the passageways 42 of the `rcontiguous bolted Yinsulators so that its ends abut the bolts 43 therein to keep the tie rods from longitudinal shifting.

A ser-ies of -ver-tical-ly spaced apart electric -resistance heating elements 46 are disposed within the heating 'chamber deiined Vby the wall Il by having their opposite edge portions received by the grooves 46 4and 4| of adjacent insulators which `are mounted on lthe rings `31. series of vertically spaced apart electric resistyance heating elements 41 are mounted within the heating chamber invertically staggered and overlapping relation Ato the series of heating elements 46. The opposite edge portions lof each heating element 41 is received `by 'the grooves 40 and 4I of the insulators 39 which are mounted on the rings 38. A diverter 43 has a lower end portion 49 of inverted cone shape and is mounted within the heating .chamber by brackets i! which are secured to thestandards .33 by bolts 5I and nuts 52.

The upper portion of the diverter 48 is circular and its outer surface 53 tapers upwardly and inwardly from the base of the inverted cone shaped portion 49 so that `the space 54 between the tapered outer surface 53 and the inner surface of the wall H progressively increases in cross-sectional area towards the outlet 21. The portion 49 of the diverter 48 :is disposed immedi- A second L ately above the annulus I9 the opening of which constitutes the inlet of the casing.

1 The electric circuit forthe heating elements is of the three 'phase type and comprises electric conductors 55, 56 and 51 which are connected to terminals 58, 59 and 60, respectively, and to the heating elements. The terminals are mounted in a terminal box 6l and are connected to a suitable -source of electric current. The terminal lbox'il is vmounted on the base plate l1 by screws or the like '62. The conductors are covered by lporcelain beads orfsleeves 63.

A switch 64 controls the supply of electric current'to the heating elements 46 and 41. A pipe 55 has one end connected to the outlet rings 21 and its opposite end `is adapted to `open to the atmosphere .or to recirculate ithe Lair 'into =the room in which the device is located. Adamper 56 is pivotally mounted within .the pipe '65 -by a rod 61. Oneend-of the rod 61 projects 'from the pipe 65 -and is secured in aslot 68-'of'a 'link-BSby a cotter pin 11G. A pin 1I has one end portion riding in the slot 68 and secured `therein bya cotter pin 12. The opposite end -portion of the pin 1I is connected to thefupperend-ofalever 1'3. The lower end of the lever 1-31is operatively connected to a thermostat 14, rthe operation of `which is automatically 'controlled by the temperature /o the air within the pipe 65.

In order to cperatethe thermostat 14 and-the damper 66, there is provided a thermocouple-disposed within the pipe i with Wires -15 and 15 extending outwardly therefrom and intoa switch box 11, where they are connected electrically in a suitable manner to operate said thermostat. This thermostatic control does not per se vconstitute -a part ofthe present invention, and-'itis Ato be understood that 'any suitable 'automatic 'means may be employed wherebyt'he temperature ofthe air within the pipe 4'65 automatically actuates a thermostat-.ic means lto 'thereby operate 'a damper to 'open the 4same ydependent upon 'the temperature of the air within the pipe 65. 'The thermostatic control is set so that `the air within the pipe E5 reaches such a high temperature -th'at all germs 'are killed before'the thermocoup'le operates to open damper 66 to allow the air to 'flow through Lthe 'system and to the open atmosphere or to somesuitable recirculation apparatus.

1n the operation of the device the sterilizer can be suspended by `the brackets 32 from the ceiling of the room in Ywhich it is desired to sterilize the air. The vitiated air will normally ascend `toward the ceiling and will enter the opening 'in the annulus t9.

The incoming air will Lbe directed by the inverted cone shape portion '49 of the .diverter '4.8 to the lowermost of the Yheating elements 4.6 and 41 immediately upon its entrance into the heating chamber.

The lowermost 'heating elements 46 and '41 increase the temperature of the incoming air Tby convection, that is the lowermost ,portion of the wall lil is heated by the Ylowermost 'heating elements and this heat is imparted to the 'incoming air. At this entrance 'zone the column of air is relatively narrow and the heat from the lowermost heat-ing elements reaches the entire 'column of air. From this point on, due "to the upward and inward tapering of the -wall 53 of the diverter, the air passage 54 progressively increases in crosssectional area so as to permit the a-ir to 'expand as its temperature increases.

As the air flows through the passageway V54, l-t

will be subjected continuously to the heat -emahating from the heating elements of the Staggered series of elements 46 and 47. As the air progresses upwardly through the passageway 54 in addition to being heated by convection the mass of air adjacent the diverter 48 will be heated by conduction.

The thermostat 14 can be set to become effective for opening the damper 6B at any desired tempertaure; the preferable range is somewhere between 600 to 700 degrees F. When the air within the heating chamber has reached the proper selected temperature, the thermostat Will be operated to pull the lever 'I3 downwardly so that the link 69 is rocked in a clockwise direction and the damper, through its connection 61 with the link 69, is moved to open position. The air which has then been properly sterilized, due to the destruction of the entrained germs, fiows through the pipe 65 and is discharged into the open atmosphere or is recirculated to a fresh air supply of the building. By means of the switch E4, the flow of electric current to the heating elements 46 and 41 can be manually controlled. If desired, a fan can be mounted within the pipe 65 for supplementing the movement of the air from the pipe 65. The device has a capacity of about 75 cubic feet of air per minute.

It will be noted from Figures 3 and 7 that the heating elements 4B and 41, the diverter 48, the inlet I9 and their supporting structure and the terminal box 6I are all carried by the base plate l'l which in turn is detachably mounted on the casing so that by loosening the bolts I8 the base plate with the heating elements, diverter, inlet and terminal box and its connections can be withdrawn from the casing as an integral unit. Repairs can then be made with facility o'r if the repairs required are too extensive to be made in situ, a new unit can be installed in the casing.

The thermocouple can be adjusted so that the L damper will be opened when the temperature in the pipe reaches about 650 F. but the damper will not be closed until the temperature in the pipe 65 falls below 600 F. This will assure that the temperature in the casing will be sufficiently high to kill the germs in the air before releasing the air to the outside atmosphere and also that the egress of the hot air will not be stopped before the air in the casing has cooled suiciently to prevent burning out of the various parts disposed within the casing.

It is obvious that various changes and modications may be made in the details of construction and design of the above specifically described embodiment of this invention without departing from the spirit thereof, such changes and modifications being restricted only by the scope of the following claims.

What I claim is:

1. An improved air sterilizer comprising a casing having an inlet opening at one end and an outlet opening at its opposite end, an annular series of vertically spaced apart heating elements mounted within the casing between its open ends, and a second annular series of vertically spaced apart heating elements mounted within the casing in vertically spaced apart and horizontally offset relation to the heating elements of the first series of heating elements.

2. An improved air sterilizer as claimed in claim 1 characterized by the fact that the inner surfaceof said casing is substantially vertical, that a diverter is mounted within the casing having a leading end of inverted cone shape and that the rear portion of the diverter has an upwardly and inwardly tapering wall cooperating withV the inner vertical surface of said casing so that a passageway of progressively increasing size is provided between the inner surface of the casing and the tapered wall of the diverter.

. 3. An improved air sterilizer as claimed in claim 2 characterized by the fact that a pipe is connected to the outlet opening of the casing and that a thermostatically controlled damper automatically opens and closes the passageway through the pipe.

4. An improved air sterilizer as claimed in claim 10 characterized by the fact that a series of vertically spaced apart rings are secured to the inner faces ofy saidl standards, that a second series of vertically spaced apart rings are secured to the outer faces of said standards and in staggered relation to the first series of rings, that: insulators are mounted on each series of rings, that ther seriesA of heating elementsare mounted on the insulators Iron" the first series of rings, and :that a Ysecond series of heating elements are mounted on the insulators on the second series of rings.

5. An improved air sterilizer as claimed in claim 4 characterized by the fact that each of said insulators has grooves in its upper and lower surfaces for the reception of the heating elements.

6. An improved air sterilizer as claimed in claim 5 characterized by the fact that the insulators on each ring are disposed in an annular row, that every third insulator has a bolt passing therethrough for securing it to its ring, that each insulator has a square shaped longitudinal passageway therethrough, and that a square shaped tie rod has its opposite end portions received by the square passageways in the bolted insulators, its opposite ends abutting the bolts in the bolted insulators and its intermediate portion extending through the square shaped passageways in the intermediate insulators.

7. An improved air sterilizer comprising a casing having an air inlet and an air outlet, a base plate detachably mounted on said casing and having an opening therethrough, a ring mounted on the base plate, a circular plate mounted on the base plate and having an opening therein, an annulus mounted on the circular plate and communicating with the opening therein and extending through the opening in the base plate, a plurality of standards secured to the circular plate and the base plate, electric heating elements secured to the standards, a diverter mounted on the standards, a terminal box secured to the base plate, terminals mounted in said box, and electric conductors connected to the terminals and the heating elements.

8. An improved air sterilizer comprising a heating chamber having spaced apart walls, heating elements disposed within said chamber, a reinforcing band secured to the inner face of each wall adjacent the lower end thereof, an insulating ring secured to the lower ends of the walls and the reinforcing bands for closing the lower end of the space between the walls, insulating material secured to the under face of said insulating ring, a top plate for closing the upper end of the space between the walls, and insulating material filling the space between said walls.

9. An improved air sterilizer comprising a casing having an air inlet at one end and an air outlet at its opposite end, a series of vertically spaced apart heating elements disposed within the casing between its inlet and its outlet, the

ower'rst fisi'clf fleeting-r, elemeiits being dis*- posed inwardly off and cls'l-yadjacent toV said inlet, and v a divertermountd within the casing and havinga leading end1 off invrted' cone shape closelyV adjacent' to said inlet andsrrundd by said lowe'lmost heating element,` Where'byftlincomng air' idirected by the leadingfndof said diverter directly againstaidl'ewerrost hea-ting element. l I l 10'. An-irnprove'dair ster-1112er comprising: a casiing having an air inlet at one end;- andan` air outlet at its oppositefend;- abaseA plate detachably mountedon said casing; a series of" heatingf efe@ ments supported'l by saidlbasey piate for heating the air as-it owsdfrom the: inlet to the-outlet of said casing, a diverterv supported by 's'avd base platel for directing,r4 tzlie incoming air' into direct contact' with saidheatingf elements, and; a plu@ rality: of circumferentially' spaced' apart" standards supported. by saidfbasevplate and suppert-4 ingv said heating: elements; H. HAINES Sr EFE-RENCES CITED The following referermesv are of record in th le of this` patenti UNITED STATES PATENTS Number Name n Date. Bloon'e May 16, 1922` Dutton Sept. 12,- 1922 Prefontaine June 241',4 1924 Johnson Mar. 151927- Shepherd` Feb. 21,A 1928 Edwards Jan. 14, 1930 'I une Mar. 4, 1930 Hegel" Apr. 161935 Hynes Augi 20, 1935 Parsons O'ct. 20,` 1936 Taylor Sept. 21., 1948 FGREIGN. PATENTS,

Cuntry y Date Switzerland Feb. 20`, 1912 

